syscall tracing: update tests
[lttng-tools.git] / src / bin / lttng-sessiond / kernel.c
CommitLineData
20fe2104
DG
1/*
2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
3 *
d14d33bf
AM
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License, version 2 only,
6 * as published by the Free Software Foundation.
20fe2104
DG
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
d14d33bf
AM
13 * You should have received a copy of the GNU General Public License along
14 * with this program; if not, write to the Free Software Foundation, Inc.,
15 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
20fe2104
DG
16 */
17
8c0faa1d 18#define _GNU_SOURCE
6c1c0768 19#define _LGPL_SOURCE
20fe2104 20#include <errno.h>
7b395890 21#include <fcntl.h>
20fe2104
DG
22#include <stdlib.h>
23#include <stdio.h>
f34daff7 24#include <string.h>
8c0faa1d 25#include <unistd.h>
77c7c900 26#include <inttypes.h>
20fe2104 27
990570ed 28#include <common/common.h>
db758600 29#include <common/kernel-ctl/kernel-ctl.h>
c052142c 30#include <common/kernel-ctl/kernel-ioctl.h>
42224349 31#include <common/sessiond-comm/sessiond-comm.h>
1e307fab 32
2f77fc4b 33#include "consumer.h"
4771f025 34#include "kernel.h"
6dc3064a 35#include "kernel-consumer.h"
096102bd 36#include "kern-modules.h"
834978fd 37#include "utils.h"
20fe2104 38
d65106b1 39/*
050349bb 40 * Add context on a kernel channel.
d65106b1
DG
41 */
42int kernel_add_channel_context(struct ltt_kernel_channel *chan,
645328ae 43 struct ltt_kernel_context *ctx)
d65106b1
DG
44{
45 int ret;
46
0525e9ae
DG
47 assert(chan);
48 assert(ctx);
49
d65106b1 50 DBG("Adding context to channel %s", chan->channel->name);
645328ae 51 ret = kernctl_add_context(chan->fd, &ctx->ctx);
d65106b1 52 if (ret < 0) {
b579acd9 53 if (errno != EEXIST) {
df0f840b 54 PERROR("add context ioctl");
b579acd9
DG
55 } else {
56 /* If EEXIST, we just ignore the error */
57 ret = 0;
58 }
d65106b1
DG
59 goto error;
60 }
61
645328ae 62 cds_list_add_tail(&ctx->list, &chan->ctx_list);
d65106b1
DG
63
64 return 0;
65
66error:
67 return ret;
68}
69
20fe2104 70/*
050349bb
DG
71 * Create a new kernel session, register it to the kernel tracer and add it to
72 * the session daemon session.
20fe2104 73 */
8c0faa1d 74int kernel_create_session(struct ltt_session *session, int tracer_fd)
20fe2104
DG
75{
76 int ret;
77 struct ltt_kernel_session *lks;
78
0525e9ae
DG
79 assert(session);
80
54012638 81 /* Allocate data structure */
dec56f6c 82 lks = trace_kernel_create_session();
20fe2104 83 if (lks == NULL) {
54012638 84 ret = -1;
20fe2104
DG
85 goto error;
86 }
87
54012638 88 /* Kernel tracer session creation */
20fe2104
DG
89 ret = kernctl_create_session(tracer_fd);
90 if (ret < 0) {
df0f840b 91 PERROR("ioctl kernel create session");
20fe2104
DG
92 goto error;
93 }
94
20fe2104 95 lks->fd = ret;
7b395890
DG
96 /* Prevent fd duplication after execlp() */
97 ret = fcntl(lks->fd, F_SETFD, FD_CLOEXEC);
98 if (ret < 0) {
df0f840b 99 PERROR("fcntl session fd");
7b395890
DG
100 }
101
53632229 102 lks->id = session->id;
3bd1e081 103 lks->consumer_fds_sent = 0;
8c0faa1d 104 session->kernel_session = lks;
8c0faa1d
DG
105
106 DBG("Kernel session created (fd: %d)", lks->fd);
20fe2104
DG
107
108 return 0;
109
110error:
5f62c685
DG
111 if (lks) {
112 trace_kernel_destroy_session(lks);
113 }
20fe2104
DG
114 return ret;
115}
116
117/*
050349bb
DG
118 * Create a kernel channel, register it to the kernel tracer and add it to the
119 * kernel session.
20fe2104 120 */
050349bb 121int kernel_create_channel(struct ltt_kernel_session *session,
fdd9eb17 122 struct lttng_channel *chan)
20fe2104
DG
123{
124 int ret;
125 struct ltt_kernel_channel *lkc;
20fe2104 126
0525e9ae
DG
127 assert(session);
128 assert(chan);
0525e9ae 129
54012638 130 /* Allocate kernel channel */
fdd9eb17 131 lkc = trace_kernel_create_channel(chan);
54012638 132 if (lkc == NULL) {
20fe2104
DG
133 goto error;
134 }
135
ecc48a90 136 DBG3("Kernel create channel %s with attr: %d, %" PRIu64 ", %" PRIu64 ", %u, %u, %d, %d",
fdd9eb17 137 chan->name, lkc->channel->attr.overwrite,
173af62f
DG
138 lkc->channel->attr.subbuf_size, lkc->channel->attr.num_subbuf,
139 lkc->channel->attr.switch_timer_interval, lkc->channel->attr.read_timer_interval,
ecc48a90 140 lkc->channel->attr.live_timer_interval, lkc->channel->attr.output);
173af62f 141
54012638 142 /* Kernel tracer channel creation */
f3ed775e 143 ret = kernctl_create_channel(session->fd, &lkc->channel->attr);
20fe2104 144 if (ret < 0) {
df0f840b 145 PERROR("ioctl kernel create channel");
20fe2104
DG
146 goto error;
147 }
148
54012638 149 /* Setup the channel fd */
20fe2104 150 lkc->fd = ret;
7b395890
DG
151 /* Prevent fd duplication after execlp() */
152 ret = fcntl(lkc->fd, F_SETFD, FD_CLOEXEC);
153 if (ret < 0) {
df0f840b 154 PERROR("fcntl session fd");
7b395890
DG
155 }
156
54012638 157 /* Add channel to session */
8c0faa1d
DG
158 cds_list_add(&lkc->list, &session->channel_list.head);
159 session->channel_count++;
fb5f35b6 160 lkc->session = session;
20fe2104 161
00e2e675 162 DBG("Kernel channel %s created (fd: %d)", lkc->channel->name, lkc->fd);
20fe2104
DG
163
164 return 0;
165
166error:
5f62c685
DG
167 if (lkc) {
168 free(lkc->channel);
169 free(lkc);
170 }
54012638 171 return -1;
20fe2104 172}
f34daff7
DG
173
174/*
050349bb
DG
175 * Create a kernel event, enable it to the kernel tracer and add it to the
176 * channel event list of the kernel session.
49d21f93 177 * We own filter_expression and filter.
f34daff7 178 */
050349bb
DG
179int kernel_create_event(struct lttng_event *ev,
180 struct ltt_kernel_channel *channel)
f34daff7
DG
181{
182 int ret;
183 struct ltt_kernel_event *event;
f34daff7 184
0525e9ae
DG
185 assert(ev);
186 assert(channel);
187
62499ad6 188 event = trace_kernel_create_event(ev);
54012638 189 if (event == NULL) {
d87bfb32 190 ret = -1;
f34daff7
DG
191 goto error;
192 }
193
f3ed775e
DG
194 ret = kernctl_create_event(channel->fd, event->event);
195 if (ret < 0) {
bd29c13d
DG
196 switch (errno) {
197 case EEXIST:
198 break;
199 case ENOSYS:
200 WARN("Event type not implemented");
201 break;
8197a339
DG
202 case ENOENT:
203 WARN("Event %s not found!", ev->name);
204 break;
bd29c13d 205 default:
d87bfb32
DG
206 PERROR("create event ioctl");
207 }
208 ret = -errno;
e953ef25 209 goto free_event;
8c0faa1d 210 }
f34daff7 211
d0ae4ea8 212 event->type = ev->type;
f3ed775e 213 event->fd = ret;
7b395890
DG
214 /* Prevent fd duplication after execlp() */
215 ret = fcntl(event->fd, F_SETFD, FD_CLOEXEC);
216 if (ret < 0) {
df0f840b 217 PERROR("fcntl session fd");
7b395890
DG
218 }
219
f3ed775e
DG
220 /* Add event to event list */
221 cds_list_add(&event->list, &channel->events_list.head);
cbbbb275
DG
222 channel->event_count++;
223
e953ef25
DG
224 DBG("Event %s created (fd: %d)", ev->name, event->fd);
225
226 return 0;
227
228free_event:
229 free(event);
230error:
d87bfb32 231 return ret;
e953ef25
DG
232}
233
26cc6b4e 234/*
050349bb 235 * Disable a kernel channel.
26cc6b4e
DG
236 */
237int kernel_disable_channel(struct ltt_kernel_channel *chan)
238{
239 int ret;
240
0525e9ae
DG
241 assert(chan);
242
26cc6b4e
DG
243 ret = kernctl_disable(chan->fd);
244 if (ret < 0) {
df0f840b 245 PERROR("disable chan ioctl");
26cc6b4e
DG
246 ret = errno;
247 goto error;
248 }
249
250 chan->enabled = 0;
251 DBG("Kernel channel %s disabled (fd: %d)", chan->channel->name, chan->fd);
252
253 return 0;
254
255error:
256 return ret;
257}
258
d36b8583 259/*
050349bb 260 * Enable a kernel channel.
d36b8583
DG
261 */
262int kernel_enable_channel(struct ltt_kernel_channel *chan)
263{
264 int ret;
265
0525e9ae
DG
266 assert(chan);
267
d36b8583 268 ret = kernctl_enable(chan->fd);
54d01ffb 269 if (ret < 0 && errno != EEXIST) {
df0f840b 270 PERROR("Enable kernel chan");
d36b8583
DG
271 goto error;
272 }
273
274 chan->enabled = 1;
275 DBG("Kernel channel %s enabled (fd: %d)", chan->channel->name, chan->fd);
276
277 return 0;
278
279error:
280 return ret;
281}
282
19e70852 283/*
050349bb 284 * Enable a kernel event.
19e70852
DG
285 */
286int kernel_enable_event(struct ltt_kernel_event *event)
287{
288 int ret;
289
0525e9ae
DG
290 assert(event);
291
19e70852 292 ret = kernctl_enable(event->fd);
42224349
DG
293 if (ret < 0) {
294 switch (errno) {
295 case EEXIST:
f73fabfd 296 ret = LTTNG_ERR_KERN_EVENT_EXIST;
42224349
DG
297 break;
298 default:
299 PERROR("enable kernel event");
300 break;
301 }
19e70852
DG
302 goto error;
303 }
304
305 event->enabled = 1;
306 DBG("Kernel event %s enabled (fd: %d)", event->event->name, event->fd);
307
308 return 0;
309
310error:
d36b8583 311 return ret;
19e70852
DG
312}
313
e953ef25 314/*
050349bb 315 * Disable a kernel event.
e953ef25 316 */
19e70852 317int kernel_disable_event(struct ltt_kernel_event *event)
e953ef25
DG
318{
319 int ret;
19e70852 320
0525e9ae
DG
321 assert(event);
322
19e70852 323 ret = kernctl_disable(event->fd);
42224349
DG
324 if (ret < 0) {
325 switch (errno) {
326 case EEXIST:
f73fabfd 327 ret = LTTNG_ERR_KERN_EVENT_EXIST;
42224349
DG
328 break;
329 default:
330 PERROR("disable kernel event");
331 break;
332 }
19e70852 333 goto error;
e953ef25 334 }
f3ed775e 335
19e70852
DG
336 event->enabled = 0;
337 DBG("Kernel event %s disabled (fd: %d)", event->event->name, event->fd);
338
f34daff7
DG
339 return 0;
340
341error:
d36b8583 342 return ret;
f34daff7 343}
aaf26714 344
6e911cad 345
ccf10263
MD
346int kernel_track_pid(struct ltt_kernel_session *session, int pid)
347{
348 DBG("Kernel track PID %d for session id %" PRIu64 ".",
349 pid, session->id);
350 return kernctl_track_pid(session->fd, pid);
351}
352
353int kernel_untrack_pid(struct ltt_kernel_session *session, int pid)
354{
355 DBG("Kernel untrack PID %d for session id %" PRIu64 ".",
356 pid, session->id);
357 return kernctl_untrack_pid(session->fd, pid);
358}
359
a5dfbb9d
MD
360ssize_t kernel_list_tracker_pids(struct ltt_kernel_session *session,
361 int **_pids)
362{
363 int fd, ret;
364 int pid;
365 ssize_t nbmem, count = 0;
366 FILE *fp;
367 int *pids;
368
369 fd = kernctl_list_tracker_pids(session->fd);
370 if (fd < 0) {
371 PERROR("kernel tracker pids list");
372 goto error;
373 }
374
375 fp = fdopen(fd, "r");
376 if (fp == NULL) {
377 PERROR("kernel tracker pids list fdopen");
378 goto error_fp;
379 }
380
381 nbmem = KERNEL_TRACKER_PIDS_INIT_LIST_SIZE;
382 pids = zmalloc(sizeof(*pids) * nbmem);
383 if (pids == NULL) {
384 PERROR("alloc list pids");
385 count = -ENOMEM;
386 goto end;
387 }
388
389 while (fscanf(fp, "process { pid = %u; };\n", &pid) == 1) {
390 if (count >= nbmem) {
391 int *new_pids;
392 size_t new_nbmem;
393
394 new_nbmem = nbmem << 1;
395 DBG("Reallocating pids list from %zu to %zu entries",
396 nbmem, new_nbmem);
397 new_pids = realloc(pids, new_nbmem * sizeof(*new_pids));
398 if (new_pids == NULL) {
399 PERROR("realloc list events");
400 free(pids);
401 count = -ENOMEM;
402 goto end;
403 }
404 /* Zero the new memory */
405 memset(new_pids + nbmem, 0,
406 (new_nbmem - nbmem) * sizeof(*new_pids));
407 nbmem = new_nbmem;
408 pids = new_pids;
409 }
410 pids[count++] = pid;
411 }
412
413 *_pids = pids;
414 DBG("Kernel list tracker pids done (%zd pids)", count);
415end:
416 ret = fclose(fp); /* closes both fp and fd */
417 if (ret) {
418 PERROR("fclose");
419 }
420 return count;
421
422error_fp:
423 ret = close(fd);
424 if (ret) {
425 PERROR("close");
426 }
427error:
428 return -1;
429}
430
aaf26714 431/*
050349bb
DG
432 * Create kernel metadata, open from the kernel tracer and add it to the
433 * kernel session.
aaf26714 434 */
a4b92340 435int kernel_open_metadata(struct ltt_kernel_session *session)
aaf26714
DG
436{
437 int ret;
74024a21 438 struct ltt_kernel_metadata *lkm = NULL;
aaf26714 439
0525e9ae
DG
440 assert(session);
441
54012638 442 /* Allocate kernel metadata */
a4b92340 443 lkm = trace_kernel_create_metadata();
54012638 444 if (lkm == NULL) {
aaf26714
DG
445 goto error;
446 }
447
54012638 448 /* Kernel tracer metadata creation */
f3ed775e 449 ret = kernctl_open_metadata(session->fd, &lkm->conf->attr);
aaf26714 450 if (ret < 0) {
74024a21 451 goto error_open;
aaf26714
DG
452 }
453
8c0faa1d 454 lkm->fd = ret;
7b395890
DG
455 /* Prevent fd duplication after execlp() */
456 ret = fcntl(lkm->fd, F_SETFD, FD_CLOEXEC);
457 if (ret < 0) {
df0f840b 458 PERROR("fcntl session fd");
7b395890
DG
459 }
460
aaf26714 461 session->metadata = lkm;
8c0faa1d 462
00e2e675 463 DBG("Kernel metadata opened (fd: %d)", lkm->fd);
8c0faa1d
DG
464
465 return 0;
466
74024a21
DG
467error_open:
468 trace_kernel_destroy_metadata(lkm);
8c0faa1d 469error:
54012638 470 return -1;
8c0faa1d
DG
471}
472
473/*
050349bb 474 * Start tracing session.
8c0faa1d
DG
475 */
476int kernel_start_session(struct ltt_kernel_session *session)
477{
478 int ret;
479
0525e9ae
DG
480 assert(session);
481
8c0faa1d
DG
482 ret = kernctl_start_session(session->fd);
483 if (ret < 0) {
df0f840b 484 PERROR("ioctl start session");
8c0faa1d
DG
485 goto error;
486 }
487
488 DBG("Kernel session started");
489
490 return 0;
491
492error:
493 return ret;
494}
495
f3ed775e 496/*
050349bb 497 * Make a kernel wait to make sure in-flight probe have completed.
f3ed775e
DG
498 */
499void kernel_wait_quiescent(int fd)
500{
501 int ret;
502
503 DBG("Kernel quiescent wait on %d", fd);
504
505 ret = kernctl_wait_quiescent(fd);
506 if (ret < 0) {
df0f840b 507 PERROR("wait quiescent ioctl");
f3ed775e
DG
508 ERR("Kernel quiescent wait failed");
509 }
510}
511
d0254c7c 512/*
050349bb 513 * Kernel calibrate
d0254c7c
MD
514 */
515int kernel_calibrate(int fd, struct lttng_kernel_calibrate *calibrate)
516{
517 int ret;
518
0525e9ae
DG
519 assert(calibrate);
520
d0254c7c
MD
521 ret = kernctl_calibrate(fd, calibrate);
522 if (ret < 0) {
df0f840b 523 PERROR("calibrate ioctl");
d0254c7c
MD
524 return -1;
525 }
526
527 return 0;
528}
529
530
f3ed775e 531/*
f3ed775e
DG
532 * Force flush buffer of metadata.
533 */
534int kernel_metadata_flush_buffer(int fd)
535{
536 int ret;
537
169d2cb7
DG
538 DBG("Kernel flushing metadata buffer on fd %d", fd);
539
f3ed775e
DG
540 ret = kernctl_buffer_flush(fd);
541 if (ret < 0) {
00e2e675 542 ERR("Fail to flush metadata buffers %d (ret: %d)", fd, ret);
f3ed775e
DG
543 }
544
545 return 0;
546}
547
548/*
050349bb 549 * Force flush buffer for channel.
f3ed775e
DG
550 */
551int kernel_flush_buffer(struct ltt_kernel_channel *channel)
552{
553 int ret;
554 struct ltt_kernel_stream *stream;
555
0525e9ae
DG
556 assert(channel);
557
f3ed775e
DG
558 DBG("Flush buffer for channel %s", channel->channel->name);
559
560 cds_list_for_each_entry(stream, &channel->stream_list.head, list) {
561 DBG("Flushing channel stream %d", stream->fd);
562 ret = kernctl_buffer_flush(stream->fd);
563 if (ret < 0) {
df0f840b 564 PERROR("ioctl");
f3ed775e
DG
565 ERR("Fail to flush buffer for stream %d (ret: %d)",
566 stream->fd, ret);
567 }
568 }
569
570 return 0;
571}
572
8c0faa1d 573/*
050349bb 574 * Stop tracing session.
8c0faa1d
DG
575 */
576int kernel_stop_session(struct ltt_kernel_session *session)
577{
578 int ret;
579
0525e9ae
DG
580 assert(session);
581
8c0faa1d
DG
582 ret = kernctl_stop_session(session->fd);
583 if (ret < 0) {
584 goto error;
585 }
586
587 DBG("Kernel session stopped");
588
589 return 0;
590
591error:
592 return ret;
593}
594
595/*
050349bb
DG
596 * Open stream of channel, register it to the kernel tracer and add it
597 * to the stream list of the channel.
8c0faa1d 598 *
050349bb 599 * Return the number of created stream. Else, a negative value.
8c0faa1d 600 */
f3ed775e 601int kernel_open_channel_stream(struct ltt_kernel_channel *channel)
8c0faa1d 602{
00e2e675 603 int ret, count = 0;
8c0faa1d
DG
604 struct ltt_kernel_stream *lks;
605
0525e9ae
DG
606 assert(channel);
607
5a47c6a2 608 while ((ret = kernctl_create_stream(channel->fd)) >= 0) {
00e2e675 609 lks = trace_kernel_create_stream(channel->channel->name, count);
8c0faa1d 610 if (lks == NULL) {
799e2c4f
MD
611 ret = close(ret);
612 if (ret) {
613 PERROR("close");
614 }
8c0faa1d
DG
615 goto error;
616 }
617
618 lks->fd = ret;
7b395890
DG
619 /* Prevent fd duplication after execlp() */
620 ret = fcntl(lks->fd, F_SETFD, FD_CLOEXEC);
621 if (ret < 0) {
df0f840b 622 PERROR("fcntl session fd");
7b395890
DG
623 }
624
1624d5b7
JD
625 lks->tracefile_size = channel->channel->attr.tracefile_size;
626 lks->tracefile_count = channel->channel->attr.tracefile_count;
627
54012638 628 /* Add stream to channe stream list */
8c0faa1d
DG
629 cds_list_add(&lks->list, &channel->stream_list.head);
630 channel->stream_count++;
8c0faa1d 631
00e2e675
DG
632 /* Increment counter which represent CPU number. */
633 count++;
634
635 DBG("Kernel stream %s created (fd: %d, state: %d)", lks->name, lks->fd,
636 lks->state);
54012638 637 }
8c0faa1d
DG
638
639 return channel->stream_count;
640
641error:
54012638 642 return -1;
8c0faa1d
DG
643}
644
645/*
050349bb 646 * Open the metadata stream and set it to the kernel session.
8c0faa1d 647 */
f3ed775e 648int kernel_open_metadata_stream(struct ltt_kernel_session *session)
8c0faa1d
DG
649{
650 int ret;
651
0525e9ae
DG
652 assert(session);
653
8c0faa1d
DG
654 ret = kernctl_create_stream(session->metadata->fd);
655 if (ret < 0) {
df0f840b 656 PERROR("kernel create metadata stream");
8c0faa1d
DG
657 goto error;
658 }
659
660 DBG("Kernel metadata stream created (fd: %d)", ret);
661 session->metadata_stream_fd = ret;
7b395890
DG
662 /* Prevent fd duplication after execlp() */
663 ret = fcntl(session->metadata_stream_fd, F_SETFD, FD_CLOEXEC);
664 if (ret < 0) {
df0f840b 665 PERROR("fcntl session fd");
7b395890 666 }
aaf26714
DG
667
668 return 0;
669
670error:
54012638 671 return -1;
aaf26714 672}
2ef84c95
DG
673
674/*
9f19cc17 675 * Get the event list from the kernel tracer and return the number of elements.
2ef84c95 676 */
9f19cc17 677ssize_t kernel_list_events(int tracer_fd, struct lttng_event **events)
2ef84c95 678{
53efb85a 679 int fd, ret;
9f19cc17
DG
680 char *event;
681 size_t nbmem, count = 0;
2ef84c95 682 FILE *fp;
9f19cc17 683 struct lttng_event *elist;
2ef84c95 684
0525e9ae
DG
685 assert(events);
686
2ef84c95
DG
687 fd = kernctl_tracepoint_list(tracer_fd);
688 if (fd < 0) {
df0f840b 689 PERROR("kernel tracepoint list");
2ef84c95
DG
690 goto error;
691 }
692
693 fp = fdopen(fd, "r");
694 if (fp == NULL) {
df0f840b 695 PERROR("kernel tracepoint list fdopen");
61b73b12 696 goto error_fp;
2ef84c95
DG
697 }
698
699 /*
700 * Init memory size counter
701 * See kernel-ctl.h for explanation of this value
702 */
6725fe19 703 nbmem = KERNEL_EVENT_INIT_LIST_SIZE;
ba7f0ae5 704 elist = zmalloc(sizeof(struct lttng_event) * nbmem);
3b870559
MD
705 if (elist == NULL) {
706 PERROR("alloc list events");
707 count = -ENOMEM;
708 goto end;
709 }
2ef84c95 710
53efb85a 711 while (fscanf(fp, "event { name = %m[^;]; };\n", &event) == 1) {
6725fe19 712 if (count >= nbmem) {
3b870559 713 struct lttng_event *new_elist;
53efb85a 714 size_t new_nbmem;
3b870559 715
53efb85a
MD
716 new_nbmem = nbmem << 1;
717 DBG("Reallocating event list from %zu to %zu bytes",
718 nbmem, new_nbmem);
719 new_elist = realloc(elist, new_nbmem * sizeof(struct lttng_event));
3b870559 720 if (new_elist == NULL) {
df0f840b 721 PERROR("realloc list events");
3b870559
MD
722 free(event);
723 free(elist);
61b73b12
MD
724 count = -ENOMEM;
725 goto end;
2ef84c95 726 }
53efb85a
MD
727 /* Zero the new memory */
728 memset(new_elist + nbmem, 0,
729 (new_nbmem - nbmem) * sizeof(struct lttng_event));
730 nbmem = new_nbmem;
3b870559 731 elist = new_elist;
2ef84c95 732 }
99497cd0
MD
733 strncpy(elist[count].name, event, LTTNG_SYMBOL_NAME_LEN);
734 elist[count].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
67b9d018 735 elist[count].enabled = -1;
9f19cc17 736 count++;
3b870559 737 free(event);
2ef84c95
DG
738 }
739
9f19cc17 740 *events = elist;
ced2f820 741 DBG("Kernel list events done (%zu events)", count);
61b73b12 742end:
799e2c4f
MD
743 ret = fclose(fp); /* closes both fp and fd */
744 if (ret) {
745 PERROR("fclose");
746 }
9f19cc17 747 return count;
2ef84c95 748
61b73b12 749error_fp:
799e2c4f
MD
750 ret = close(fd);
751 if (ret) {
752 PERROR("close");
753 }
2ef84c95
DG
754error:
755 return -1;
756}
096102bd
DG
757
758/*
759 * Get kernel version and validate it.
760 */
761int kernel_validate_version(int tracer_fd)
762{
763 int ret;
764 struct lttng_kernel_tracer_version version;
c052142c 765 struct lttng_kernel_tracer_abi_version abi_version;
096102bd
DG
766
767 ret = kernctl_tracer_version(tracer_fd, &version);
768 if (ret < 0) {
769 ERR("Failed at getting the lttng-modules version");
770 goto error;
771 }
772
773 /* Validate version */
c052142c
MD
774 if (version.major != VERSION_MAJOR) {
775 ERR("Kernel tracer major version (%d) is not compatible with lttng-tools major version (%d)",
776 version.major, VERSION_MAJOR);
096102bd 777 goto error_version;
096102bd 778 }
c052142c
MD
779 ret = kernctl_tracer_abi_version(tracer_fd, &abi_version);
780 if (ret < 0) {
781 ERR("Failed at getting lttng-modules ABI version");
782 goto error;
783 }
784 if (abi_version.major != LTTNG_MODULES_ABI_MAJOR_VERSION) {
785 ERR("Kernel tracer ABI version (%d.%d) is not compatible with expected ABI major version (%d.*)",
786 abi_version.major, abi_version.minor,
787 LTTNG_MODULES_ABI_MAJOR_VERSION);
788 goto error;
789 }
790 DBG2("Kernel tracer version validated (%d.%d, ABI %d.%d)",
791 version.major, version.minor,
792 abi_version.major, abi_version.minor);
096102bd
DG
793 return 0;
794
795error_version:
096102bd
DG
796 ret = -1;
797
798error:
799 return ret;
800}
335a95b7
MD
801
802/*
803 * Kernel work-arounds called at the start of sessiond main().
804 */
805int init_kernel_workarounds(void)
806{
8936c33a 807 int ret;
335a95b7
MD
808 FILE *fp;
809
810 /*
811 * boot_id needs to be read once before being used concurrently
812 * to deal with a Linux kernel race. A fix is proposed for
813 * upstream, but the work-around is needed for older kernels.
814 */
815 fp = fopen("/proc/sys/kernel/random/boot_id", "r");
816 if (!fp) {
817 goto end_boot_id;
818 }
819 while (!feof(fp)) {
820 char buf[37] = "";
821
8936c33a
DG
822 ret = fread(buf, 1, sizeof(buf), fp);
823 if (ret < 0) {
824 /* Ignore error, we don't really care */
825 }
335a95b7 826 }
799e2c4f
MD
827 ret = fclose(fp);
828 if (ret) {
829 PERROR("fclose");
830 }
335a95b7 831end_boot_id:
335a95b7
MD
832 return 0;
833}
2f77fc4b
DG
834
835/*
836 * Complete teardown of a kernel session.
837 */
838void kernel_destroy_session(struct ltt_kernel_session *ksess)
839{
840 if (ksess == NULL) {
841 DBG3("No kernel session when tearing down session");
842 return;
843 }
844
845 DBG("Tearing down kernel session");
846
07b86b52 847 /*
15dc512a
DG
848 * Destroy channels on the consumer if at least one FD has been sent and we
849 * are in no output mode because the streams are in *no* monitor mode so we
850 * have to send a command to clean them up or else they leaked.
07b86b52 851 */
15dc512a 852 if (!ksess->output_traces && ksess->consumer_fds_sent) {
07b86b52
JD
853 int ret;
854 struct consumer_socket *socket;
855 struct lttng_ht_iter iter;
856
857 /* For each consumer socket. */
d069d577 858 rcu_read_lock();
07b86b52
JD
859 cds_lfht_for_each_entry(ksess->consumer->socks->ht, &iter.iter,
860 socket, node.node) {
861 struct ltt_kernel_channel *chan;
862
863 /* For each channel, ask the consumer to destroy it. */
864 cds_list_for_each_entry(chan, &ksess->channel_list.head, list) {
865 ret = kernel_consumer_destroy_channel(socket, chan);
866 if (ret < 0) {
867 /* Consumer is probably dead. Use next socket. */
868 continue;
869 }
870 }
871 }
d069d577 872 rcu_read_unlock();
07b86b52
JD
873 }
874
2f77fc4b
DG
875 /* Close any relayd session */
876 consumer_output_send_destroy_relayd(ksess->consumer);
877
878 trace_kernel_destroy_session(ksess);
879}
fb5f35b6
DG
880
881/*
882 * Destroy a kernel channel object. It does not do anything on the tracer side.
883 */
884void kernel_destroy_channel(struct ltt_kernel_channel *kchan)
885{
886 struct ltt_kernel_session *ksess = NULL;
887
888 assert(kchan);
889 assert(kchan->channel);
890
891 DBG3("Kernel destroy channel %s", kchan->channel->name);
892
893 /* Update channel count of associated session. */
894 if (kchan->session) {
895 /* Keep pointer reference so we can update it after the destroy. */
896 ksess = kchan->session;
897 }
898
899 trace_kernel_destroy_channel(kchan);
900
901 /*
902 * At this point the kernel channel is not visible anymore. This is safe
903 * since in order to work on a visible kernel session, the tracing session
904 * lock (ltt_session.lock) MUST be acquired.
905 */
906 if (ksess) {
907 ksess->channel_count--;
908 }
909}
6dc3064a
DG
910
911/*
912 * Take a snapshot for a given kernel session.
913 *
2a06df8d 914 * Return 0 on success or else return a LTTNG_ERR code.
6dc3064a
DG
915 */
916int kernel_snapshot_record(struct ltt_kernel_session *ksess,
d07ceecd
MD
917 struct snapshot_output *output, int wait,
918 uint64_t nb_packets_per_stream)
6dc3064a 919{
2a06df8d 920 int err, ret, saved_metadata_fd;
6dc3064a
DG
921 struct consumer_socket *socket;
922 struct lttng_ht_iter iter;
923 struct ltt_kernel_metadata *saved_metadata;
924
925 assert(ksess);
926 assert(ksess->consumer);
927 assert(output);
928
929 DBG("Kernel snapshot record started");
930
931 /* Save current metadata since the following calls will change it. */
932 saved_metadata = ksess->metadata;
933 saved_metadata_fd = ksess->metadata_stream_fd;
934
935 rcu_read_lock();
936
937 ret = kernel_open_metadata(ksess);
938 if (ret < 0) {
939 ret = LTTNG_ERR_KERN_META_FAIL;
940 goto error;
941 }
942
943 ret = kernel_open_metadata_stream(ksess);
944 if (ret < 0) {
945 ret = LTTNG_ERR_KERN_META_FAIL;
946 goto error_open_stream;
947 }
948
949 /* Send metadata to consumer and snapshot everything. */
950 cds_lfht_for_each_entry(ksess->consumer->socks->ht, &iter.iter,
951 socket, node.node) {
952 struct consumer_output *saved_output;
953 struct ltt_kernel_channel *chan;
6dc3064a
DG
954
955 /*
956 * Temporarly switch consumer output for our snapshot output. As long
957 * as the session lock is taken, this is safe.
958 */
959 saved_output = ksess->consumer;
960 ksess->consumer = output->consumer;
961
962 pthread_mutex_lock(socket->lock);
963 /* This stream must not be monitored by the consumer. */
07b86b52 964 ret = kernel_consumer_add_metadata(socket, ksess, 0);
6dc3064a 965 pthread_mutex_unlock(socket->lock);
07b86b52 966 /* Put back the saved consumer output into the session. */
6dc3064a
DG
967 ksess->consumer = saved_output;
968 if (ret < 0) {
969 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
970 goto error_consumer;
971 }
972
973 /* For each channel, ask the consumer to snapshot it. */
974 cds_list_for_each_entry(chan, &ksess->channel_list.head, list) {
07b86b52 975 pthread_mutex_lock(socket->lock);
6dc3064a 976 ret = consumer_snapshot_channel(socket, chan->fd, output, 0,
5c786ded
JD
977 ksess->uid, ksess->gid,
978 DEFAULT_KERNEL_TRACE_DIR, wait,
d07ceecd 979 nb_packets_per_stream);
07b86b52 980 pthread_mutex_unlock(socket->lock);
6dc3064a
DG
981 if (ret < 0) {
982 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
2a06df8d
DG
983 (void) kernel_consumer_destroy_metadata(socket,
984 ksess->metadata);
6dc3064a
DG
985 goto error_consumer;
986 }
987 }
988
989 /* Snapshot metadata, */
07b86b52 990 pthread_mutex_lock(socket->lock);
6dc3064a 991 ret = consumer_snapshot_channel(socket, ksess->metadata->fd, output,
5c786ded 992 1, ksess->uid, ksess->gid,
d07ceecd 993 DEFAULT_KERNEL_TRACE_DIR, wait, 0);
07b86b52 994 pthread_mutex_unlock(socket->lock);
6dc3064a
DG
995 if (ret < 0) {
996 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
997 goto error_consumer;
998 }
07b86b52
JD
999
1000 /*
1001 * The metadata snapshot is done, ask the consumer to destroy it since
1002 * it's not monitored on the consumer side.
1003 */
1004 (void) kernel_consumer_destroy_metadata(socket, ksess->metadata);
6dc3064a
DG
1005 }
1006
fac41e72
DG
1007 ret = LTTNG_OK;
1008
6dc3064a
DG
1009error_consumer:
1010 /* Close newly opened metadata stream. It's now on the consumer side. */
2a06df8d
DG
1011 err = close(ksess->metadata_stream_fd);
1012 if (err < 0) {
6dc3064a
DG
1013 PERROR("close snapshot kernel");
1014 }
1015
1016error_open_stream:
1017 trace_kernel_destroy_metadata(ksess->metadata);
1018error:
1019 /* Restore metadata state.*/
1020 ksess->metadata = saved_metadata;
1021 ksess->metadata_stream_fd = saved_metadata_fd;
1022
1023 rcu_read_unlock();
1024 return ret;
1025}
834978fd
DG
1026
1027/*
1028 * Get the syscall mask array from the kernel tracer.
1029 *
1030 * Return 0 on success else a negative value. In both case, syscall_mask should
1031 * be freed.
1032 */
1033int kernel_syscall_mask(int chan_fd, char **syscall_mask, uint32_t *nr_bits)
1034{
1035 assert(syscall_mask);
1036 assert(nr_bits);
1037
1038 return kernctl_syscall_mask(chan_fd, syscall_mask, nr_bits);
1039}
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